1. Field of the Invention
The present invention relates to a linear slide fastener, wherein coil-shaped or zigzag-shaped fastener elements of a particular shape are formed with monofilament of thermoplastic resin and the fastener elements are attached to a side edge of a fastener tape with fixing yarn of various type.
2. Description of the Related Art
According to a coil-shaped slide fastener as disclosed in Japanese Patent Publication No. 49-23874, as shown in FIG. 14, by providing a stepped portion 8xe2x80x2 in an upper leg portion 5xe2x80x2 of each of the fastener elements 2xe2x80x2, a portion of the fastener element 2xe2x80x2 on a side of a coupling head is formed to be thick while a portion on the side of a connecting portion 7xe2x80x2 is formed to be thin. A core thread 28xe2x80x2 is inserted between the upper leg portion 5xe2x80x2 and a lower leg portion 6xe2x80x2 on the side of the connecting portion 7xe2x80x2 that are formed to be thin, and sewed to the side edge of the fastener tape 13xe2x80x2. Then, a horn is lowered to apply pressure to the leg portions 5xe2x80x2 6xe2x80x2 and connecting portions 7xe2x80x2 of the fastener elements 2xe2x80x2 around the core thread 28xe2x80x2. Then, while the fastener elements 2xe2x80x2 are heated, the fastener elements 2xe2x80x2, sewing yarn 15xe2x80x2 and fastener tape 13xe2x80x2 are fused together by ultrasonic processing.
According to coil-shaped fastener elements as disclosed in Japanese Patent Publication No. 54-20895, with providing a stepped portion 8xe2x80x3 in an upper leg portion 5xe2x80x3 of each of the fastener elements 2xe2x80x3, a portion of the fastener element 2xe2x80x3 on a side of the coupling head 4xe2x80x3 is formed to be thick, while a portion thereof on a side of the connecting portion 7xe2x80x3 is formed to be thin. Then, the thin leg portion on the side of the connecting portion 7xe2x80x3 is sewed to a side edge of the fastener tape 13xe2x80x3 with sewing yarn 15xe2x80x3.
In the coil-shaped slide fastener shown in FIG. 14 and as described above, the coil-shaped fastener elements 2xe2x80x2 are disposed in such a state that each of the upper leg portions 5xe2x80x2 is parallel to each of the corresponding lower leg portions 6xe2x80x2 at a section from the corresponding coupling head 4xe2x80x2 to the stepped portion 8xe2x80x2 in a center thereof. Thus, a mating coupling head 4xe2x80x2 cannot be inserted smoothly at the time of coupling operation. Therefore, a sliding action of the slider becomes heavy so that it cannot be operated smoothly. Further, because the core thread 28xe2x80x2 inserted through the fastener elements 2xe2x80x2 is fused at a section from the stepped portion formed thin to the connecting portion 7xe2x80x2, a coupling head 4xe2x80x2 does not make an elastic contact with the mating coupling head 4xe2x80x2 at the time of coupling. Therefore, an cushion effect can not be expected, thus a smooth coupling can not be achieved.
In the coil-shaped slide fastener shown in FIG. 15, like the above described example, the fastener elements 2xe2x80x3 are disposed in such a state that each of the upper leg portions 5xe2x80x3 is parallel to each of the corresponding lower leg portions 6xe2x80x3 at a section from the coupling head 4xe2x80x3 to the stepped portion 8xe2x80x3 in a center thereof. Thus, a mating coupling head cannot be inserted smoothly at the time of coupling operation. Thus, a sliding operation of the slider becomes heavy, so that it cannot be operated smoothly. Further, because no core thread exists, the fastener elements 2xe2x80x3 are likely to be loose.
Accordingly, the present invention has been achieved in views of the above problems. Therefore, a main object of the present invention is to provide a linear slide fastener, wherein upon coupling operation, a coupling head of each of linear fastener elements in the slide fastener can be inserted into a coupling space of a mating coupling head quickly so that the coupling operation of the fastener elements can be carried out smoothly, thereby enabling to operate the slide fastener lightly, preventing an excessive invasion of the coupling head, and preventing a fixing yarn for fixing the fastener elements from being worn by a sliding of the slider, so as to ensure a long term use thereof.
Further, an object of the present invention is to provide a linear slide fastener, wherein the fastener elements are fixed firmly by specifying a use state of the fixing yarn for fixing the linear fastener elements onto a fastener tape and by applying the fixing yarn to various types of slide fasteners.
Furthermore, an object of the present invention is to provide a linear slide fastener, wherein different types of linear slide fasteners with beautiful appearance can be obtained by specifying configurations of the linear fastener elements in the linear slide fasteners.
Still further, an object of the present invention is to provide a linear slide fastener, wherein even if a pushing force is applied to the linear fastener elements in a coupling state, the coupling state is prevented from being broken by the core thread inserted through the linear fastener elements and the core thread can act as a cushion when the coupling heads couple each other so as to ensure a smooth and flexible sliding operation.
Still further, an object of the present invention is to provide a linear slide fastener, wherein the core thread inserted through the linear fastener elements in the coupling space is always protruded in an advantageous state so as to maintain a cushion state.
Still further, an object of the present invention is to provide a linear slide fastener, wherein fixing yarn disposed between the linear fastener elements can act as a cushion when the coupling heads couple each other so as to ensure a flexible and smooth sliding operation of the slider.
To achieve the above objects, according to the present invention, there is provided a linear slide fastener, wherein various kinds of linear fastener elements are formed of thermoplastic resin monofilament; with providing a stepped portion in a center of an upper leg portion of each of the linear fastener elements, a portion of the fastener element on a side of a coupling head is formed to be thick while a portion thereof on a side of a connecting portion is formed to be thin; a protruded portion protruded into a coupling space between the upper leg portion and the lower leg portion is provided on an inner face of the upper leg portion; a slope portion is formed such that the coupling space between the upper leg portion and the lower leg portion is expanded gradually from an inside of an upper portion of the coupling head to a base portion of the protruded portion; and the fastener elements are fixed to a fastener tape at the upper leg portion and the lower leg portion at the connecting portion side that are formed thin with fixing yarn.
Further, according to the present invention, there is provided a linear slide fastener, wherein the linear fastener elements are sewed on a surface of a side edge of the fastener tape using a sewing yarn as the fixing yarn for fixing the linear fastener elements.
Alternatively, according to the present invention, there is provided a linear slide fastener, wherein the linear fastener elements are woven into a side edge of the fastener tape using weaving yarn as the fixing yarn for fixing the linear fastener elements.
Further alternatively, according to the present invention, there is provided a linear slide fastener, wherein the linear fastener elements are knitted into a side edge of the fastener tape using warp knitting yarn as the fixing yarn for fixing the linear fastener elements.
Further, according to the present invention, there is provided a linear slide fastener, wherein the linear fastener elements are in a form of coil-shaped fastener elements produced by winding a monofilament in a coil-shaped shape.
Alternatively, according to the present invention, there is provided a linear slide fastener, wherein the linear fastener elements are in a form of zigzag shaped fastener elements produced by bending a monofilament in a zigzag shape.
Further, according to the present invention, there is provided a linear slide fastener, wherein a side edge of a core thread inserted between the upper leg portions and lower leg portions of the linear fastener elements is protruded toward the coupling heads beyond the protruded portions.
Furthermore, according to the present invention, there is provided a linear slide fastener, wherein a needle yarn of multi-thread chain stitches urges the core thread in the linear fastener elements such that the side edge of the core thread is always protruded.
Still further, according to the present invention, there is provided a linear slide fastener, wherein a side edge of the fixing yarn disposed between adjacent ones of the linear fastener elements is protruded toward the coupling heads beyond the protruded portions.